The lemony slush is nothing fancy: It’s made of water, sugar, lemon juice and includes real chunks of rind. But what comes in that waxy green-and-yellow paper cup — picturing a snow-topped lemon — has become a cultural icon in the state.

“Stop at the Sign of the Lemon” is the slogan. And, at the first hint of warm weather, people do. At parks, beaches, downtown Providence street corners, store parking lots and anywhere else a Del’s cart or truck franchisee sets up shop. On 90-degree days, Del’s is nothing short of a comfort food.

The frozen drink normally comes without a spoon, and none is needed: Sip, squeeze the cup, then slurp again. The lemonade will melt just enough from the heat of your hand, or the summer day.

Lemon is the original and top-selling flavor, but it also comes in watermelon, cherry, blueberry, grapefruit, peach-mango and, this year for the first time, lime. (Flavors that never made it include carrot and cantaloupe.)

Because Del’s is, well, so Rhode Island, it’s not unusual to see the trucks or carts at wedding receptions — you can spike it — birthday parties, bar mitzvahs, and troop deployments and homecomings.

As a taste of home, a mix-at-home Del’s powder — available in supermarkets — has even been shipped to local soldiers in Afghanistan and Iraq, said Joe Padula, the company’s executive vice president, who likes to say he began his career at Del’s when he was 7, picking up trash in the parking lot of the flagship location in Cranston.

The late Angelo DeLucia opened the first Del’s in 1948. After he came back from World War II, he worked as a dental technician for a time, then opened a bowling alley. To help pay the bills, he opened a 10-by-10-foot wooden stand next door and started selling the lemonade. After a few years, the business became a full-time job. The way the family tells it, DeLucia got the recipe from his grandfather, who sold a similar fruit ice at markets in Naples, Italy, in the 1840s. It’s said he used snow he collected in winter and stored in a cave, insulated with straw.

Del’s, still family-run by DeLucia’s son, Bruce, now has some 22 store locations in Rhode Island and Massachusetts, according to Padula, and the product is available in more than a dozen states. Many of the franchisees have Rhode Island roots.

Last year, Cam Crockford, formerly of Portsmouth, Rhode Island, started selling Del’s on the streets of New York City after refurbishing a 1949 Chevy Step van that’s a throwback to the original Del’s truck. “It’s as if you are stepping up to Angelo DeLucia’s first Del’s stand in 1948,” he says on his website.